Researchers Are Interested in the Effects of Wind Direction and Season

Multiple Choice

Researchers are interested in the effects of wind direction and season on ozone levels in North America. The ozone levels were recorded at locations, along with the direction of prevailing winds (E, N, S, W) and the season (winter, spring, summer, fall) . A balanced design was carried out such that each combination was observed five times. A partial ANOVA table is provided here:
$$\begin{array} { l l l l l } \text { Source } & \text { DF } & \text { SS } & \text { MS } & \text { F } \\\hline \text { Direction } & & 129 & & \\\text { Season } & & 318 & & \\\text { Interaction } & & 423 & & \\\text { Error } & & 960 & \\\hline \text { C. Total } & \quad & 1830 \end{array}$$ A profile plot for the interaction between wind direction and season is given below. Based on the plot, what would be a correct interpretation about the data?

A) There is an interaction between direction and season.
B) There is no interaction, but both main effects are highly significant.
C) There is no interaction, but the main effect for direction is highly significant.
D) There is no interaction, but the main effect for season is highly significant.